| 摘要 |
<p>In capstanless tape apparatus, a pulse generator driven by the tape feeds a comparator which generates a pulse-width modulated output according to any tape speed error and applied at 1 to a switchable amplifier T1 whose output is converted by a low-pass filter Dr, Cl into a direct voltage representing the error. A direct voltage amplifier T2, T3 acts as a controllable current source to determine the magnitude of the current supplied to the D.C. drive motor M for the tape spool, independent of the instantaneous rotor position, so as to regulate the tape speed. <IMAGE></p> |
